Contagious
by mclaheys
Summary: An infection strikes Santa Fe, and pretty much the rest of the world, and Stiles, accompanied by his abandoned dorm mate, heads out to make the long journey back to California to reunite with his father and the pack. Or, the one where zombies suddenly dominate the earth and Stiles goes fleeing back into Derek's open arms. M for smut, language, and violence. Apocalypse AU.
1. Chapter 1

He was eating Ramen when it happened. Yes, the world pretty much fucking ended, and he was eating a fucking bowl of_ Ramen_.

Now, before you judge him completely, Stiles hadn't turned on the television for a few days, given that finals were steadily approaching. If you'd seen his dorm at the time, books scattered haphazardly across the floor, papers stuck to his sweat-slicked skin, you would see that there was really no way for him to have known about the chaos erupting outside his room.

Immersed in the sounds of _Flux Pavilion_ vibrating his eardrums, he manages to get through the last page of his notes packet before Ryan bursts into the room, eyes wild and his hair matted to his damp forehead.

"We gotta go."

Now, Ryan isn't one for words most of the time. He's a simple guy (sensible khakis, button downs, seriously square glasses) who likes to play _Halo_ until the early hours of the morning, and has no qualms with ordering Mia's Pizza every night if he has to. As a scholarship child with a simplistic dream of entering the world of botany, Ryan Callahan isn't the type to sweat. Or panic.

"Dude, I'm eating." Stiles forks in another bite of Ramen as if to prove his point, watching Ryan flail around their dorm with his newly crazy eyes with mild interest. "What's with you?"

"The world is ending, Stilinski," he blurts, yanking his aged suitcase out from under his bed. "I'm getting the fuck out of here and if you want to live, I suggest you come with me."

Stiles looks at his dorm mate skeptically. "Did you do meth? Is that where you were all morning?"

Ryan pauses his frantic packing. "Take a look out the window, buddy. It's not pretty."

Indeed it wasn't.

Maybe if he'd had the yearning to go outside like he used to, Stiles would've seen this coming. Perhaps if he wasn't so focused on graduating (which is something he never thought he'd feel bad about, to be honest), Stiles would've called his dad back instead of groaning and tossing his phone under the bed. Perhaps he would've gone back to Beacon Hills a week ago, instead of seven days after the world quickly, almost overnight, became inhabited by the flesh-eating undead.

* * *

"God, you look like a tool."

That's the first thing Stiles says to Derek Hale in six months. Stepping into the darkness of the loft, he'd looked over and seen Derek, shirtless and concentrated, doing chin-ups in the corner of the front room with a fierce look in his eyes.

"Long time, no see," the barely-sweating Alpha quips, feet landing perfectly balanced on the floor of his living room. "Did you forget something here? Now that I think about it, it's probably been thrown away. The amount of cleaning we do in six months tends to be pretty extensive."

And if Derek sounds bitter, that's because he is.

"What, have you been counting the days since I left?" Stiles tries to sound casually sarcastic, but his grimace fucks it up. "Look, I'm sorry for not calling."

"Or texting, or facetiming, or even fucking writing a letter." Derek means for the words to hurt, but they fall flat. He then sighs. "Why are you here?"

Stiles shifts for a moment, then ventures deeper into the familiar loft. "I missed you."

And just like that, Stiles is naked on the couch with Derek nestled deep inside of him, lips still tangled together despite their sweaty mess of limbs and Derek's sharp thrusts up into his younger partner. Every trace of Stiles that Derek had managed to erase came back in that measly two hours, his clean, familiar scent clinging to every surface, every floorboard of the loft.

And when he left the Monday after, it took another six fucking months for it to go away.

* * *

"So what, we're just going to walk out into that?" Stiles questions, after taking one look outside and quickly drawing all the curtains. "That's your plan? There's fucking...zombies outside, and you're just going to waltz down to your car and hope they don't kill you?"

Ryan stops his hasty packing, brushing the lock of mocha hair out of his face that had come loose from his ponytail. "What, do you have a better plan?"

He doesn't, but he knows that he could use the little window of time that they have to make a better one. He's used to knocking shitty plans out of the water and replacing them with his own. "Just stop running around like a madman, okay? We need to figure out a way to get out of this fucking mess that won't end in us being a ten course meal for those things, alright? Can you manage that?"

Ryan hesitates, but only for a slight second before nodding. He sits on the well-worn couch that they'd shared for the last two years, burying his face into his hands. "My dad called, that's why I was gone all morning. Him and my mom and sister are leaving for Colorado. We have extended family there, I was planning on leaving to meet up with them, but someone said that Colorado is a suicide mission."

"The phones work?" Stiles questions, whipping around to look at his friend (can he call him that?). He supposes he should feel bad about Ryan being left behind by his family, but the thought of being able to contact his own overrides that.

Pulling out his cellphone, he dials his father's number.

"_Stiles? Oh thank god you're okay. Are you okay? Where are you?_" Hearing his father's questions flooding out would've been overwhelming if he wasn't so damn relieved to hear his voice.

"I'm fine, dad, really. I'm still in Santa Fe, but my dorm mate needs to leave to find his family and I'm pretty sure I'm going to head out too. Are you still in Beacon Hills? Is everyone okay?" Stiles cradles the phone to his ear, pacing back and forth like he's on a mission to wear a hole in the ugly blue carpet.

"_We're fine. Melissa and Scott came to get me, we're holed up at the Hale boy's loft. When are you leaving? Is it safe to leave? Stiles, I want you home more than anything but if it's not safe for you to leave, then don't do it, god damnit!_"

"Dad, I'm leaving, and I'll be there as soon as I can. Just don't leave the loft unless you absolutely have to, okay? Dad? Are you still there?" Stiles pulls the phone from his ear once the steady sound of static fills his ears, chucking the phone at the floor with a string of curses.

"What? What happened?" Ryan asks, looking up with fearful eyes.

Stiles runs a hand through his already mussed hair with a sigh. "I'm guessing the phone lines are down. Okay seriously, the next time we're studying, you need to go the fuck outside and make sure the world is still intact."

Ryan glares for a moment, before standing up and resuming his packing. "How are we going to get out of here?"

Stiles glances at the door, where Ryan had huffed and puffed as he shoved his dresser in front of it, then heads to their mini fridge and begins shoving the small bit of food they have left into one of his book bags.

"First off, are you going to Denver?" Stiles asks, zipping up the book bag and looking at Ryan. He feels a pang of sympathy at the downright miserable look on his face.

"I don't know," Ryan moans brokenly, resting his face in his hands. "My dad said to hole up somewhere safe until he could call again. He wanted to see if Denver was safe before I met up with them. But if the phones aren't working...God, I don't know. I'm not even close to my family. They kind of just...raised me, you know?"

Stiles doesn't know. He'd always been close to his dad, and his mom before she died, but he nods sympathetically anyway. "Come to Beacon Hills with me. California. It'll be safe there. Maybe the phones will be working again once we get there, and you can call your dad."

Stiles feels selfish for a moment because he knows asking Ryan to accompany him is simply because he's downright terrified of making the long trip to California by himself, and if the phones were down now then there probably isn't any hope of them working no matter where they go. But Ryan nods vigorously and Stiles pushes away his guilt, because maybe two hopeful apocalypse survivors will have more luck than just one.

* * *

"You're majoring in History?" Derek comments incredulously, pausing nuzzling Stiles's neck to look down at him.

The pale boy shifts in his lover's embrace, tracing his index finger over Derek's jawline. "Yeah. I mean, I'm good at it. And I enjoy it, so why not?"

Derek takes hold of Stiles's wandering hand, pressing sweet kisses to the tips of his fingers in a way that's very much unlike Derek. But obviously, one could say that the ritual habit he has of pounding Stiles into his mattress is quite unlike him as well.

"When do you have to go back?" Derek murmurs, settling back into the pillows and pulling Stiles to his chest.

"Next Friday. I have to visit my dad a lot while I'm here, but I'm all yours otherwise," Stiles mumbles into Derek's skin, causing a shiver to go down the alpha's spine. "Why? D'you miss me?"

"Of course." Derek can't help but stare deep into those amber eyes after he speaks, his fingers twining with Stiles's long, and surprisingly less clumsy, ones.

"I wish I didn't have to leave. I hate being away from you."

Moments later, Derek's lips are attacking his neck and he's thrusting deep into Stiles's welcoming body, the moans that escape their lips evaporating into the air that's thick with arousal.

He'd never say it, but Derek hated being away from him too.

* * *

"So that's the plan?" Ryan questions. "Take the back stairs, shove our shit into your jeep, and get the hell out of dodge?"

Stiles nods, scratching the back of his neck uneasily. "Yeah, pretty much."

"How the fuck is that any different than my plan?" Ryan bursts out, throwing his hands up into the air quite dramatically.

"I don't know, damn! I just needed time to process!" Stiles shoots back. "Besides, you were ready to go marching out the front doors with a butter knife. At least I thought about discretion."

"Jesus Christ. We're so going to die."

Stiles pauses the pacing he'd resumed, biting his lower lip uneasily.

"Yeah, probably."

* * *

**There you have it. Some flashbacks included, apocalyptic freak outs, and some implied Sterek smut. Weeeee~**


	2. Chapter 2

"He's coming back? As in _here_? To Beacon Hills?" Derek paces in front of the couch, having a hard time processing what Stiles's father had just told him. "Why? Is it safe? Should he even leave his dorm?"

The Sheriff scrubs a hand over his tired face with a sigh. "Honestly? I don't know. The phone lines went down. I have no idea what's going on out there, or what will happen to my son if he tries to make his way here. But it's not like I can call him back and tell him to stay put, now can I?"

Derek wants to glare, really. But his chest is too locked up with worry and it _sucks_. Cora puts a calming hand on his shoulder, her eyes tired but alert.

"This is Stiles we're talking about," Scott speaks up, brown eyes wide with hope. "He never does anything without a plan. He's smart, smarter than all of us at least. He'll make it here. I'm sure of it."

Allison squeezes his hand with a tiny smile, much to her father's dismay. Which, on any other day, would piss Derek Hale off. Who has time to dictate their daughter's love life when the world is being overrun by the undead?

"He could die," Derek finishes firmly, saying what he knows everyone else is thinking. "And if that happens, it's on us."

He retreats back up the stairs to his room, leaving his pack in huddled in the living room, soaking up each other's presences as though that alone will ward off any of the disease ridden bodies that had once been humans.

"He's right, you know," Isaac murmurs, wide eyes cast down to the carpet. "The big cities have it the worst. Santa Fe is probably a dead zone."

"Isaac!" Allison chastises, after glancing at the sinking look on the Sheriff's face. "We have to stay positive. Stiles will come home. Just like we all made it here, he will too."

And they all grasp at strings, gazing at the elevator doors like Stiles will come strolling through them with that big goofy grin on his face at any moment.

But he doesn't.

* * *

Back before the death and the zombies and sheer terror (well, that was always there, but...technicalities), Stiles loved basking in the sun on the front lawn of the university, planning his next visit home. As much as he loved the dry heat of Santa Fe, he missed the muggy, damp air of Beacon Hills.

And without really thinking, he pulled out his cell phone and pressed speed dial 2.

"Stiles?" His voice sounds thick with sleep, but it still sounds like Derek nonetheless.

Stiles grins, sprawling back out across the impossibly green grass, reveling in his ex-lover's voice. "I'll be back in Beacon Hills in a few days. It being Spring Break, and whatnot."

He's greeted by silence, and his smile fades.

"You're coming home? For how long?" Derek sounds more alert now.

"Uh, I dunno. I didn't really think about it. Our Spring Break is like a week and two days, so I guess for a week? How long would you want me to stay?" Stiles realizes he's rambling, and pauses to steady his beating heart. "I mean, if you want to see me, that is."

Derek sucks in a breath. "Why wouldn't I?"

"I don't know," Stiles replies with a snicker, his goofy grin re-appearing. For a fleeting moment, he thought Derek was going to say _why would I_? And to be honest, he doesn't have an answer. He'd been kind of...absent.

"I miss you."

Stiles thinks he hears him wrong. "You what? Did Derek Hale just say he misses me? As in _me_, Stiles Stilinski?"

"You heard me," Derek growls.

And they talk like that for another hour, with Derek sitting on the couch, the phone pressed so tight against his ear that one would think he was trying to stick it inside, and with Stiles sprawled on the too-green campus grass, sun warming his already rosy cheeks.

Back then, they had that luxury.

* * *

"We have those steak knives," Ryan suggests as Stiles races around the dorm, desperately trying to find anything that would suffice as a weapon. "And your bat."

"Really, Ryan? Steak knives and a bat?" Stiles whirls around, staring hard at the shorter male. "What do you think this is, Top fucking Chef: Home Run Edition?"

Ryan pauses, trying to digest that. "Um, no?"

Stiles narrows his eyes. "Listen here, bud. This is game time, I need something with a little more kick than a dinky steak knife or your childhood baseball dreams."

"You have a lacrosse stick?" Ryan offers.

Stiles claps him on the back, nodding. "Now we're talking."

Twenty minutes later, they have the small quantity of food that they had left, a few extra pairs of clothes, some personal effects, and all the pseudo-weapons that they could find, or carry.

"This isn't going to work," Ryan says miserably, his bat in hand while Stiles brandishes his one-time winning lacrosse stick.

"Hey now, don't get all mopey-doomsday on me now. Just pretend you're playing Halo!" Stiles encourages, giving Ryan a thumbs up. "Except, y'know, real. And with zombies."

Ryan turns away rather quickly after that.

Gathering their belongings, courage, and wits, they slide the dresser out of the way from where it had blocked the exit, swinging the windowless door to their dorm open and step out into the deserted hallways.

"Do you think they can't open doors?" Ryan asks, peering uneasily around him.

Stiles thinks about that for a second, then shrugs. "Who cares? We just need to get to the Jeep. Run more, talk later."

The setting is all too familiar, running down empty school hallways with items that one could barely call weapons, their imminent deaths looming before them.

God, shit storms really _do_ follow him everywhere.

Trying not to dwell on the depressing hell his life seemed to have become in the last five or so years, Stiles keeps his eyes peeled, legs moving, and lacrosse stick up. On the way down the emergency stairs, they thankfully meet no zombies, or diseased flesh eaters, _whatever_. But getting down that last flight, the noises of tearing flesh, the broken moans of the dying and the dead, and abandoned car horns fills their ears.

"God, that's like straight out of a Sci-Fi movie," Stiles mutters, gritting his teeth.

Ryan shifts the bat into his left hand, staring expectantly at Stiles. "So how do we do this? Like, do we distract them? Run for our lives and hope we make it?"

"Most likely the latter. I'm not suddenly having any life saving ideas."

"Right. Great. We can make it, right? I'm coordinated, you're fast. You are fast, aren't you?"

Well, Stiles _was_. He's not so sure anymore. While he still tries to make time to work out and keep in shape, he hadn't exactly gone to take a long, soul-finding jog in quite a while. Not to mention the daily indulgences that most likely will come back to bite him, i.e. alcohol, copious amounts of pizza, the occasional joint, and, sweet Jesus, fucking _Swiss Rolls_.

"Oh yeah, I'm fast. Like, lightning fast. Pull the trigger and I'm around the track like _Roadrunner_." Stiles stretches awkwardly, the small space they happened to find themselves in not the best area to spread out. He tries to ignore the disbelieving look on Ryan's face; he needs courage, not the constant reminder that they're most likely about to get torn to pieces.

"I am _so_ not ready for this," Ryan moans, thumping the back of his head against the wall behind him. "I just wanted to study plants. Why zombies? Why not a flesh-eating Hibiscus?"

"I tried smoking one of those once!" Stiles butts in, biting his tongue at the look that Ryan shoots him. "Okay, we just need to get this over with. The parking lot is right across the street. It's just up and out, you know? Like, maybe they're like flies. They'll bother you until you hold up the fly swatter, and then they fuck off."

"But they eat brains, not _Dorito _crumbs," Ryan points out, brows lifting over the black frames of his glasses.

Stiles pauses. "Less talking, more running. Try to remember that, Negative Nancy."

The two boys (men? What exactly do you call two barely-20-year-olds brandishing lacrosse sticks and baseball bats?) brace themselves, both hands pressed against the double doors that lead to the back of the dorm. And when they do shove them open (who knew people left so much shit piled up against building doors in the thick of a zombie apocalypse?), the sunlight greets them with a warm familiarity. Of course, so does the copious amount of door squeakage.

"That's beautiful, honestly. Sheer perfection," Stiles mutters bitterly at the creaky doors that lead to the dumpsters, right across from the student parking zone. "Let me take a look. Stay here, and seriously dude, if you move, I will feed you to those things. Even your _Pantene _commercial hair."

Missing the visible horror that flickers across Ryan's face, Stiles, as quietly as humanly possible, shuffles around the two overflowing dumpsters to the corner leading to the right side of the building. Peeking around, he still finds no visible signs of life.

"I don't see anything, maybe they all- Holy shit!" Stiles stumbles backwards a bit, tripping over a stack of empty milk crates that had obviously once been used for an art project, and lands right on his ass. "Move! Dude, get your bat!"

Behind Ryan, one of those..._things_ drags itself out from behind an abandoned campus security truck, mouth drenched in blood, skin barely hanging onto its face. It's teeth crack together as it snaps its jaws, lurching forward (rather quickly for something that is supposed to be, well, _dead_). What Stiles finds to be the most horrific part of the creature is in fact its eyes. The whites have clouded over, pupils blown out so much that they swallow the iris completely, the only color left being the thin, pinkish ring around the area where the iris would have been.

"Oh shit, oh shit, oh_shitohshitohshit_," Ryan fumbles for his bat, tripping over himself to get away from the snapping, growling person. Or zombie. _Whatever_.

Stiles launches himself up from the ground, lacrosse stick wobbling in his hands. "Run, run, fucking _run_!"

And finally, his end of the world-friend complies, scrambling after him on trembling legs. Of course, the sound of clacking teeth and grisly flesh splattering onto the ground is a big alert for the other undead to drag themselves back out into the open, hissing and snapping at the two boys who frantically try to remember how to work their legs.

"We're going to die, Stilinski, we're dead!" Ryan literally cries, tears leaking from the corners of his eyes. "I haven't even gotten to touch a boob! Or tell my parents that I'm gay!"

On a normal day, Stiles would've stopped to process the complete lack of sense that Ryan just made, but today, clearly, is not a normal day. The sun feels too hot on his skin as his legs tear across the lawn separating them from the parking lot, the blinding white of the other dorms surrounding his own burns his eyes, and the too-green grass all of sudden really seems _too fucking green_. But he keeps running, because hell, he's used to it by now. He ran from wolves, from murderous lizards, his own mother's death. It was conventional, almost like the familiar scent of home that one is immersed in after a long vacation away.

"Ryan, you will touch a boob, you will suck a dick one day I swear to god, but Jesus I don't care if that cramp is splitting you in half, just keep _fucking running_!" Stiles pants out, because how the fuck far away is this parking lot?

For another moment, they're running, but seconds later they're finally at Stiles's Jeep, the distance between them and the flesh eaters that seemed to swarm within minutes seems kind of comforting.

"Keys, keys, keys..." Stiles mutters, digging through his bag.

Ryan taps his foot impatiently on the pavement, drumming his fingers on the car door as he frantically looks around at the infected that are steadily lurching closer. "Dude, hurry, oh my god! If you don't hurry, I'm literally going to shit in my pants. _In my pants_. I'm so beyond serious."

Stiles's hands shake at an unbelievable rate as he digs through his book bag. "I'm trying, would it kill you to shut up for like ten seconds and let me think?"

"Think? What do you mean think? What the _hell _could you possibly need to think about? Just get the keys and let's get the fuck out of here!" Ryan's voice raises an octave in the midst of his panic.

"Well, perhaps I need to think about the slight problem that we _might_ have?" Stiles squeaks (literally, he squeaks).

Ryan whips his head around to look at Stiles so hard that he probably got whiplash. "What problem could possibly be bigger than the one we have right now? And by that I mean the fucking dead people starting to fucking _swarm around us_?"

"Well, you see, I might have...I may, possibly, you know, have forgotten the keys."

* * *

**I couldn't resist. Let me know what you thought!**


End file.
